Frequency, Predictors, Distribution, and Morphological Characteristics of Layered Culprit and Nonculprit Plaques of Patients With Acute Myocardial Infarction: In Vivo 3-Vessel Optical Coherence Tomography Study.

BACKGROUND: Subclinical atherothrombosis and plaque healing may lead to rapid plaque progression. The histopathologic healed plaque has a layered appearance when imaged using optical coherence tomography. We assessed the frequency, predictors, distribution, and morphological characteristics of optical coherence tomography layered culprit and nonculprit plaques in patients with acute myocardial infarction. METHODS: A prospective series of 325 patients with acute myocardial infarction underwent optical coherence tomography imaging of all 3 native coronary arteries. Layered plaque phenotype had heterogeneous signal-rich layered tissue located close to the luminal surface that was clearly demarcated from the underlying plaque. RESULTS: Layered plaques were detected in 74.5% of patients with acute myocardial infarction. Patients with layered culprit plaques had more layered nonculprit plaques; and they more often had preinfarction angina, ST-segment-elevation myocardial infarction, higher low-density lipoprotein cholesterol, and absence of antiplatelet therapy. Layered plaques tended to cluster in the proximal segment of the left anterior descending artery and left circumflex artery but were more uniformly distributed in the right coronary artery. As compared with nonlayered plaques, layered plaques had greater optical coherence tomography lumen area stenosis at both culprit and nonculprit sites. The frequency of layered plaque phenotype (P=0.038) and maximum area of layered tissue (P<0.001) increased from nonculprit thin-cap fibroatheromas to nonculprit ruptures to culprit ruptures. CONCLUSIONS: Layered plaques were identified in 3-quarters of patients with acute myocardial infarction, especially in the culprit plaques of patients with ST-segment-elevation myocardial infarction. Layered plaques had a limited, focal distribution in the left anterior descending artery, and left circumflex artery but were more evenly distributed in the right coronary artery and were characterized by greater lumen narrowing at both culprit and nonculprit sites. Graphic Abstract: A graphic abstract is available for this article.

Characteristics and significance of healed plaques in patients with acute coronary syndrome and stable angina: an in vivo OCT and IVUS study.

AIMS: The aim of this study was to determine the prevalence and significance of plaque with a multilayered (ML) pattern in patients with acute coronary syndrome (ACS) versus stable angina pectoris (SAP) using OCT. METHODS AND RESULTS: Two hundred and four patients (144 ACS and 60 SAP) with OCT imaging of the culprit lesions before intervention were studied. ML plaques were identified by OCT as plaque with multiple layers of distinct optical signals. ML plaque was identified in 119 out of 204 (58.3%) patients. ML plaques were more frequently observed in SAP than ACS (75% vs 51.4%, p=0.001). Patients with prior myocardial infarction (MI) had a higher incidence of ML plaque compared with those without (74.4% vs 54.5%, p=0.024). ML plaque had a higher degree of luminal stenosis (p=0.006), longer lesion length (p=0.025), more complex lesion type (B2/C) (p<0.001) on angiography and non-significant larger plaque burden (p=0.07) on IVUS compared with those without an ML pattern. CONCLUSIONS: ML plaques, indicative of prior thrombosis, were frequently identified in patients with CAD, particularly more so in SAP and those with prior MI compared with ACS. The presence of an ML pattern is a marker of a greater extent and severity of CAD, suggesting a pathogenic link between plaque healing and lesion progression.

Pre-infarction angina and culprit lesion morphologies in patients with a first ST-segment elevation acute myocardial infarction: insights from in vivo optical coherence tomography.

AIMS: This study aimed to evaluate the relationship between pre-infarction angina (PIA) and in vivo culprit lesion characteristics as assessed by intravascular optical coherence tomography (OCT) in patients with a first ST-segment elevation myocardial infarction (STEMI). METHODS AND RESULTS: A total of 305 consecutive patients with a first STEMI who underwent OCT imaging of culprit lesions during primary percutaneous coronary intervention (PCI) were prospectively enrolled. OCT findings of the culprit plaque were compared between patients with (n=206) and without PIA (n=99). Patients with PIA showed lower rates of thin-cap fibroatheroma (TCFA) (62.6% vs. 80.8%, p=0.001) and plaque rupture (56.8% vs. 72.7%, p=0.007), smaller maximum ruptured cavity areas (1.10±1.04 mm2 vs. 1.53±1.20 mm2, p=0.002), and more severe residual luminal narrowing (p=0.015) with a higher incidence of white residual thrombus (68.4% vs. 50.0%, p=0.003) at the culprit lesions than patients without PIA. No significant differences in clinical outcomes were observed at the one-year follow-up. CONCLUSIONS: In patients with a first STEMI, PIA was significantly associated with a lower incidence of TCFA and plaque rupture, a smaller ruptured cavity area, more white residual thrombi, and more severe lumen stenosis at the culprit lesions.

In vivo predictors of plaque erosion in patients with ST-segment elevation myocardial infarction: a clinical, angiographical, and intravascular optical coherence tomography study.

Aims: Plaque erosion is a significant substrate of acute coronary thrombosis. This study sought to determine in vivo predictors of plaque erosion in patients with ST-segment elevation myocardial infarction (STEMI). Methods and results: A prospective series of 822 STEMI patients underwent pre-intervention optical coherence tomography. Using established diagnostic criteria, 209 had plaque erosion (25.4%) and 564 had plaque rupture (68.6%). Plaque erosion was more frequent in women <50 years when compared with those ≥50 years of age (P = 0.009). There was a similar, but less striking, trend in men (P = 0.011). Patients with plaque erosion were more frequently current smokers but had fewer other coronary risk factors (dyslipidaemia, hypertension, chronic kidney disease, and diabetes mellitus) than those with plaque rupture. There was a preponderance of plaque erosion in the left anterior descending artery (LAD; 61.2%), whereas plaque rupture was more equally distributed in both the LAD (47.0%) and right coronary artery (43.3%). Despite the similar spatial distribution of erosions and ruptures over the lengths of the coronary arteries, plaque erosion occurred more frequently near a bifurcation (P < 0.001). In the multivariable analysis, age <50 years, current smoking, absence of other coronary risk factors, lack of multi-vessel disease, reduced lesion severity, larger vessel size, and nearby bifurcation were significantly associated with plaque erosion. Nearby bifurcation and current smoking were especially notable in men, while age <50 years was most predictive in women. Conclusions: Plaque erosion was a predictable clinical entity distinct from plaque rupture in STEMI patients, and gender-specific role of risk factors in plaque erosion should be considered.

Does spotty calcification attenuate the response of nonculprit plaque to statin therapy?: A serial optical coherence tomography study.

OBJECTIVES: The aim of this study was to determine if spotty calcification decreases the response of plaque progression to statin therapy. BACKGROUND: Previous studies showed that the presence of spotty calcification is a marker of vulnerable plaque. However, the relationship between spotty calcification and plaque progression is not clear. METHODS: Ninety-six nonculprit lipid-rich plaques in 69 patients who received serial optical coherence tomography (OCT) imaging were included. Plaques were divided into three groups: spotty calcification (n = 38), calcified (n = 12) and noncalcified (n = 46) plaques. Spotty calcification was identified by the presence of a lesion <4 mm in length with an arc of calcification <90°. Changes in plaque characteristics and fibrous cap thickness (FCT) at 6 and 12 months under statin therapy were analyzed by OCT. RESULTS: The increase of FCT was sustained from baseline to 6 and 12 months in three groups: spotty calcification (62.8 ± 20.9, 126.4 ± 84.9, and 169.2 ± 81.6 µm, respectively; P < .001), calcified (59.8 ± 17.0, 93.4 ± 51.4, and 155.2 ± 61.7 µm, respectively; P < .001) and noncalcified (60.0 ± 17.2, 125.5 ± 62.1, and 161.0 ± 80.5 µm, respectively; P < .001). Intensive statin induced a greater change in FCT at 12 months than moderate statin in the spotty calcification group (P = 0.034). The mean lipid arc decreased significantly at 12 months from baseline in the three groups (P = 0.004, P = 0.023, and P < .001, respectively). CONCLUSIONS: Statin therapy was effective for plaque stabilization in plaques with and without spotty calcification. Patients with spotty calcification benefitted more from intensive statin than from moderate statin therapy.

EROSION Study (Effective Anti-Thrombotic Therapy Without Stenting: Intravascular Optical Coherence Tomography-Based Management in Plaque Erosion): A 1-Year Follow-Up Report.

BACKGROUND: The initial EROSION study (Effective Anti-Thrombotic Therapy Without Stenting: Intravascular Optical Coherence Tomography-Based Management in Plaque Erosion) demonstrated that patients with acute coronary syndrome caused by plaque erosion might be stabilized with aspirin and ticagrelor without stenting for ≤1 month. However, a long-term evaluation of outcomes is lacking. The aim of this study was to assess whether the initial benefit of noninterventional therapy for patients with acute coronary syndrome caused by plaque erosion is maintained for ≤1 year. METHODS AND RESULTS: Among 53 patients who completed clinical follow-up, 49 underwent repeat optical coherence tomography imaging at 1 year. Median residual thrombus volume decreased significantly from 1 month to 1 year (0.3 mm3 (0.0-2.0 mm3] versus 0.1 mm3 [0.0-2.0 mm3]; P=0.001). Almost half of the patients (46.9%) had no residual thrombus at 1 year. Minimal effective flow area remained unchanged (2.1 mm2 [1.5-3.8 mm2] versus 2.1 mm2 [1.6-4.0 mm2]; P=0.152). Among 53 patients, 49 (92.5%) remained free from major adverse cardiovascular event for ≤1 year: 3 (5.7%) patients required revascularization because of exertional angina and 1 (1.9%) patient had gastrointestinal bleeding. CONCLUSIONS: One-year follow-up optical coherence tomography demonstrated a further decrease in thrombus volume between 1-month and 1-year follow-up. A majority (92.5%) of patients with acute coronary syndrome caused by plaque erosion managed with aspirin and ticagrelor without stenting remained free of major adverse cardiovascular event for ≤1 year. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifier: NCT02041650.

Clinical Significance of Lipid-Rich Plaque Detected by Optical Coherence Tomography: A 4-Year Follow-Up Study.

BACKGROUND: Lipid-rich plaque (LRP) is thought to be a precursor to cardiac events. However, its clinical significance in coronary arteries has never been systematically investigated. OBJECTIVES: This study investigated the prevalence and clinical significance of LRP in the nonculprit region of the target vessel in patients undergoing percutaneous coronary intervention (PCI). METHODS: The study included 1,474 patients from 20 sites across 6 countries undergoing PCI, who had optical coherence tomography (OCT) imaging of the target vessel. Major adverse cardiac events (MACE) were defined as a composite of cardiac death, acute myocardial infarction, and ischemia-driven revascularization. Patients were followed for up to 4 years (median of 2 years). RESULTS: Lipid-rich plaque was detected in nonculprit regions of the target vessel in 33.6% of patients. The cumulative rate of nonculprit lesion-related MACE (NC-MACE) over 48 months in patients with LRP was higher than in those without LRP (7.2% vs. 2.6%, respectively; p = 0.033). Acute coronary syndrome at index presentation (risk ratio: 2.538; 95% confidence interval [CI]: 1.246 to 5.173; p = 0.010), interruption of statin use ≥1 year (risk ratio: 4.517; 95% CI: 1.923 to 10.610; p = 0.001), and LRP in nonculprit regions (risk ratio: 2.061; 95% CI: 1.050 to 4.044; p = 0.036) were independently associated with increased NC-MACE. Optical coherence tomography findings revealed that LRP in patients with NC-MACE had longer lipid lengths (p < 0.001), wider maximal lipid arcs (p = 0.023), and smaller minimal lumen areas (p = 0.003) than LRPs in patients without MACE. CONCLUSIONS: Presence of LRP in the nonculprit regions of the target vessel by OCT predicts increased risk for future NC-MACE, which is primarily driven by revascularization for recurrent ischemia. Lipid-rich plaque with longer lipid length, wider lipid arc, and higher degree of stenosis identified patients at higher risk of future cardiac events. (The Massachusetts General Hospital Optical Coherence Tomography Registry; NCT01110538).

Impact of statins therapy on morphological changes in lipid-rich plaques stratified by 10-Year framingham risk score: A serial optical coherence tomography study.

The aim of the study was to investigate the impact of statins therapy on morphological changes of lipid-rich plaques by OCT (optical coherence tomography) in patients with known CHD (coronary heart disease), stratified by FRS. Ninety-seven lipid-rich plaques from sixty-nine patients who received statins therapy and underwent serial OCT images (baseline, 6-month and 12-month) were divided into 2 groups according to the FRS (framingham risk score): low risk group A (FRS<10%, N=35, n=45), moderate to high risk group B (FRS≥10%, N=34, n=52). Fibrous cap thickness (FCT) was measured at its thinnest part 3 times. Baseline characteristics were not different between the 2 groups. FCT sustained increased from baseline to 6-month and 12-month follow up in both group A (59.8±20.4µm, 118.3±62.5µm, and 158.8±83.4µm respectively, P<0.001) and group B (62.2±16.8µm, 125.1±78.7µm, 163.8±75.5µm respectively, P<0.001). Lipid index was significantly decreased in both group A (1862.1±1164.5, 1530.3±1108.7, 1322.9±1080.4, P<0.001) and group B (1646.6±958.5, 1535.1±1049.1, 1258.6±1045, P=0.016). The incidence of TCFA was decreased statistically in both group A (P <0.001) and group B (P <0.001). The patients with known CHD can equivalently benefit from statins therapy by stabilizing the lipid-rich plaques. Patients with moderate to high FRS might benefit more within the first year from event time.

Plaque erosion delays vascular healing after drug eluting stent implantation in patients with acute coronary syndrome: An In Vivo Optical Coherence Tomography Study.

OBJECTIVES: To compare vascular healing after drug-eluting stent (DES) implantation between plaque rupture (PR) and plaque erosion (PE). BACKGROUND: Vascular response after stent implantation in patients with PR has been extensively studied. Little is known about vascular healing after stent implantation in PE. METHODS: Sixty-five ACS patients who received optical coherence tomography (OCT) imaging of the culprit lesions both before and after stent implantation at baseline as well as at 6 months were included in this study. Patients were divided into two groups: PR (n = 19) and PE (n = 24). Prestent thrombus burden and poststent intrastent structure (ISS) volume were analyzed during the index procedure. The ratio of uncovered to total stent struts per cross-section score (RUTTS) and neointimal thickness and area were measured at follow-up. RESULTS: OCT imaging showed that compared with PR, PE showed a significantly lower prestent thrombus score (34.2 ± 19.2 vs. 68.6 ± 44.2, P = 0.009) at baseline and a smaller poststent ISS volume (0.7 ± 0.9 mm3 vs. 2.1 ± 1.9 mm3 , P = 0.019). At the 6-month follow-up, PE showed a higher incidence of RUTTS >0.3 (12.2 ± 14.4 vs. 2.0 ± 4.5%, P = 0.003), thinner neointimal thickness (0.05 ± 0.02 mm vs. 0.12 ± 0.08 mm, P = 0.002), and smaller neointimal area (0.5 ± 0.2 vs. 1.2 ± 0.9 mm2 , P = 0.004) compared with PR. In a multivariate logistic model, PE was identified as an independent predictor for RUTTS >0.3. CONCLUSIONS: PE was associated with less favorable healing following DES implantation when compared to PR at 6 months, indicating longer dual-antiplatelet therapy may be necessary for patients with PE. © 2017 Wiley Periodicals, Inc.

Chronic total occlusion is associated with a higher incidence of malapposition and uncovered stent struts: OCT findings at 6 months following DES implantation.

OBJECTIVES: To compare stent coverage and malapposition in patients with chronic total occlusion (CTO) lesions and non-CTO lesions (including lipid-rich plaque [LRP] and non-lipid-rich plaque [non-LRP]) after drug-eluting stent (DES) implantation by optical coherence tomography (OCT). BACKGROUND: Different initial lesion characteristics may be related to heterogeneous vessel responses after DES implantation. However, the vessel response in patients with CTO and non-CTO lesions after stenting is unclear. Methods We retrospectively enrolled 64 patients with 68 target lesions. All of the patients underwent OCT imaging immediate after stenting and 6 months after stenting. LRP was defined as the plaque with lipid content in ≥2 quadrants. Non-LRP consisted of fibrous, fibrocalcific plaque, and lipid plaque with less than 2 quadrants lipid content. RESULTS: The malapposition (3.0%, 2.6% vs. 0.6%, P = 0.022), tissue protrusion (15.0% vs. 11.0% vs. 6.4%, P < 0.001), and intrastent thrombus (3.8% vs. 2.4% vs. 1.1%, P = 0.012) were more frequent in the CTO and LRP groups. At 6-month follow-up, malapposition (5.0% vs. 1.0% and 0.4%, P = 0.002) and cross sections with uncovered struts (23.4% vs. 8.2% and 6.6%, P < 0.001) were most frequently observed in the CTO group. Although the incidence of stent thrombosis was non-significantly higher in the CTO group than the other two groups, no events were observed in patients with CTO. CONCLUSIONS: Patients with CTO lesions showed unfavorable responses to DES in the acute phase as well as at the 6-month follow-up, indicating the important pathological link between the original lesion morphology underneath the stents and heterogeneous artery healing. © 2017 Wiley Periodicals, Inc.

Management and Outcome of Patients With Acute Coronary Syndrome Caused by Plaque Rupture Versus Plaque Erosion: An Intravascular Optical Coherence Tomography Study.

BACKGROUND: Plaque rupture and erosion are the 2 most common mechanisms for acute coronary syndromes. However, the outcome of these 2 distinct pathologies in patients with acute coronary syndromes has never been studied. METHODS AND RESULTS: We retrospectively studied 141 patients with acute coronary syndromes who underwent optical coherence tomography (OCT) imaging of the culprit lesion prior to stenting from the Massachusetts General Hospital OCT Registry. Management (stent versus no stent), poststent OCT findings, and outcomes were compared. Among the 141 culprit lesions, rupture was found in 79 (56%) patients and erosion in 62 (44%). Stent implantation was performed in 77 (97.5%) patients with rupture versus 49 (79.0%) in those with erosion (P<0.001). Immediately after percutaneous coronary intervention, OCT showed a higher incidence of malapposition (37.5% versus 7.3%, P<0.001), thrombus (59.4% versus 14.6%, P<0.001), and protrusion (93.8% versus 73.2%, P=0.008) in the rupture group compared with the erosion group. Plaque rupture was associated with a higher incidence of no reflow or slow flow and distal embolization. Although cardiac event rates were comparable between the two groups at the 1-year follow-up, none of the erosion patients who were treated conservatively without stenting had adverse cardiac events. CONCLUSIONS: Unfavorable poststent OCT findings were more frequent in rupture patients compared with erosion patients. A subset of erosion patients who were treated conservatively without stenting remained free of adverse cardiac events for up to 1 year.

Is age an important factor for vascular response to statin therapy? A serial optical coherence tomography and intravascular ultrasound study.

OBJECTIVE: Age-related structural and functional changes in vessel wall may affect the time course of vascular response to statin therapy. In this study, we sought to compare the response of lipid-rich plaque to statin therapy in elderly versus younger patients using optical coherence tomography and intravascular ultrasound. PATIENTS AND METHODS: Sixty-nine patients who underwent serial optical coherence tomography and intravascular ultrasound at the time point of baseline, 6, and 12 months were divided into two groups according to median age: group A (age<57 years, n=35) and group B (age≥57 years, n=34). Patients were treated with intensive (atorvastatin 60 mg/day) or moderate (atorvastatin 20 mg/day or rosuvastatin 10 mg/day) statin therapy. RESULTS: A continuous increase in fibrous-cap thickness (FCT) from baseline to 12 months was observed in both groups (P<0.001, <0.001, respectively). Intensive statin induced greater percent change in FCT at 12 months than moderate statin in group B (P=0.020), but not in group A (P=0.251). Mean lipid arc decreased significantly at 12 months in two groups (P<0.001, <0.001, respectively), and this response was delayed for 6 months (P=0.403) and began to decrease during the second 6 months (P<0.001) in group B. Normalized total atheroma volume decreased significantly in group A (P<0.001), but not in group B (P=0.349). CONCLUSION: Statin therapy could stabilize lipid-rich plaque irrespective of age, and intensive statin therapy was more effective than a moderate dose of statin in increasing FCT, particularly in older patients. A delayed response of lipid content and unfavorable change in normalized total atheroma volume to statin were observed in elderly patients.

Chronic kidney disease predicts coronary plaque vulnerability: an optical coherence tomography study.

OBJECTIVE: The addition of cystatin C to creatinine in calculating the estimated glomerular filtration rate (eGFR) is known to improve the risk prediction for cardiovascular events. We sought to investigate the associations between eGFRs calculated by three Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations and coronary plaque phenotype by optical coherence tomography. PATIENTS AND METHODS: We analyzed 181 nonculprit plaques from 116 coronary artery disease patients. For each patient, the eGFR was calculated using the CKD-EPIcreatinine, CKD-EPIcystatin C, and CKD-EPIcombination equations. Patients were divided into three categories according to the eGFR calculated by each equation (≥90, 60-89, and <60 ml/min/1.73 m). RESULTS: The prevalence of thin-cap fibroatheroma (TCFA) was correlated inversely with eGFR calculated using CKD-EPIcystatin C and CKD-EPIcombination equations, but not using the CKD-EPIcreatinine equation. The best cut-off values of eGFR calculated by these two equations for differentiating TCFA were 83 and 84 ml/min/1.73 m, respectively. Compared with the CKD-EPIcreatinine equation, patients who were reclassified upward or downward categories by the CKD-EPIcystatin C equation were associated with consistently lower [adjusted odds ratio=0.27, 95% confidence interval (CI), 0.08-0.86] and higher (adjusted odds ratio=2.41, 95% CI, 1.08-5.41) prevalence for TCFA, respectively. The net reclassification improvement with cystatin C, compared with creatinine, was 0.45 (95% CI, 0.20-0.69) for TCFA, 0.38 (95% CI, 0.09-0.67) for thrombus, and 0.21 (95% CI, 0.00-0.42) for cholesterol crystals. Results were generally similar for the CKD-EPIcombination equation. CONCLUSION: The use of cystatin C alone or in combination with creatinine, compared with creatinine alone, for GFR estimation strengthens the associations between the eGFR and prevalence of vulnerable plaque characteristics.

Effective anti-thrombotic therapy without stenting: intravascular optical coherence tomography-based management in plaque erosion (the EROSION study).

AIMS: Plaque erosion, compared with plaque rupture, has distinctly different underlying pathology and therefore may merit tailored therapy. In this study, we aimed to assess whether patients with acute coronary syndrome (ACS) caused by plaque erosion might be stabilized by anti-thrombotic therapy without stent implantation. METHODS AND RESULTS: This was a single-centre, uncontrolled, prospective, proof-of concept study. Patients with ACS including ST-segment elevation myocardial infarction were prospectively enrolled. If needed, aspiration thrombectomy was performed. Patients diagnosed with plaque erosion by optical coherence tomography (OCT) and residual diameter stenosis <70% on coronary angiogram were treated with anti-thrombotic therapy without stenting. OCT was repeated at 1 month and thrombus volume was measured. The primary endpoint was >50% reduction of thrombus volume at 1 month compared with baseline. The secondary endpoint was a composite of cardiac death, recurrent ischaemia requiring revascularization, stroke, and major bleeding. Among 405 ACS patients with analysable OCT images, plaque erosion was identified in 103 (25.4%) patients. Sixty patients enrolled and 55 patients completed the 1-month follow-up. Forty-seven patients (47/60, 78.3%; 95% confidence interval: 65.8-87.9%) met the primary endpoint, and 22 patients had no visible thrombus at 1 month. Thrombus volume decreased from 3.7 (1.3, 10.9) mm3 to 0.2 (0.0, 2.0) mm3. Minimal flow area increased from 1.7 (1.4, 2.4) mm2 to 2.1 (1.5, 3.8) mm2. One patient died of gastrointestinal bleeding, and another patient required repeat percutaneous coronary intervention. The rest of the patients remained asymptomatic. CONCLUSION: For patients with ACS caused by plaque erosion, conservative treatment with anti-thrombotic therapy without stenting may be an option.

Evaluation of the characterization of thrombi in vitro by optical coherence tomography.

AIM: The purpose of this study was to provide a new assessable method of the optical coherence tomography (OCT) in characterization of thrombi with different concentrations of red blood cell (RBC). METHODS AND RESULTS: A series of thrombus models were constructed by using human blood in vitro. The thrombi were made by using human blood with different concentration of RBC (from 1% to 35%). Then tip of an FD-OCT catheter was put on the top of the thrombus to scan. After OCT being performed, all the acquired images were processed by a newly developed software to analyze the RBC levels related thrombus characteristics including attenuation, backscattering and light penetration depth. The attenuation was correlated with RBC concentration up to 9%. However, no apparent change was observed in thrombus with RBC concentration range from 10% to 35%. The same trend was seen in backscattering and penetration depth. CONCLUSIONS: FD-OCT is able to detect thrombus with different RBC concentrations up to 9%.

Changes in coronary plaque morphology in patients with acute coronary syndrome versus stable angina pectoris after initiation of statin therapy.

OBJECTIVES: The aim of this study was to examine coronary plaque morphology after initiation of statins and compare changes in plaque morphology in patients presenting with acute coronary syndrome (ACS) versus stable angina pectoris (SAP). BACKGROUND: ACS is associated with a pan-inflammatory state, and intraplaque features of inflammation correlate with coronary plaque progression. Statins have known anti-inflammatory properties that may contribute toward their beneficial cardiovascular effects. METHODS: Sixty-nine statin-naive patients (ACS, n=55; SAP, n=14) underwent baseline imaging with optical coherence tomography and intravascular ultrasound. Repeat imaging was performed at 6 and 12 months. A total of 97 nonculprit plaques were analyzed (ACS, n=74; SAP, n=23). RESULTS: Fibrous cap thickness increased in both ACS and SAP patients (all P<0.001 compared with the baseline); the ACS group showed greater percent change in fibrous cap thickness at 12 months (192.8±148.9% in ACS vs. 128.2±88.7% in SAP, P=0.018). The ACS group also showed a significant decrease in plaque microvessels (44.6% at baseline vs. 26.6% at 12 months, P=0.0386). CONCLUSION: Compared with patients with SAP, patients presenting with ACS show more favorable changes in plaque morphology after starting statin treatment. This supports a potential additive benefit of statins in the inflammatory state of ACS and reaffirms the clinical importance of statin therapy for coronary atherosclerosis.

Serial Optical Coherence Tomography and Intravascular Ultrasound Analysis of Gender Difference in Changes of Plaque Phenotype in Response to Lipid-Lowering Therapy.

Although the clinical benefit of statins have been demonstrated in both genders, gender differences in the response to statin therapy on plaque morphologic changes have not been reported. A total of 66 nonculprit plaques from 46 patients who had serial image acquisition at baseline, 6 months, and 12 months by both optical coherence tomography and intravascular ultrasound (IVUS) were included. Patients were treated with atorvastatin 60 mg (AT60) or 20 mg (AT20). The baseline characteristics were similar between women (n = 16) and men (n = 30) except for age (59.3 ± 6.8 vs 52.5 ± 10.6 years, p = 0.027) and smoking status (12.5% vs 70.0%, p <0.001). The change in fibrous cap thickness (FCT) at 12 months was significant in both groups (108.8 ± 87.4 µm, p <0.001, 91.3 ± 70.1 µm, p <0.001, respectively) without significant difference between the groups (p = 0.437). The percent change in mean lipid arc at 6 months was significantly greater in women than that in men (-12.8 ± 18.8% vs -1.56 ± 21.8%, p = 0.040). In women, the percent change of FCT in the AT20 group was similar to that in the AT60 group (182.5 ± 199.5% vs 192.9 ± 149.7%, p = 0.886). However, in men, the percent change of FCT in the AT20 group was significantly smaller than that in the AT60 group (92.2 ± 90.5% vs 225.9 ± 104.3%, p <0.001). No significant change in percent atheroma volume by IVUS was seen at 12 months in both women and men. In conclusion, statin therapy was effective in both genders for plaque stabilization at 12-month follow-up. High-intensity statin therapy may be particularly important in men.

Comparison of Intensive Versus Moderate Lipid-Lowering Therapy on Fibrous Cap and Atheroma Volume of Coronary Lipid-Rich Plaque Using Serial Optical Coherence Tomography and Intravascular Ultrasound Imaging.

Despite marked clinical benefit, reduction in atheroma volume with statin therapy is minimal. Changes in plaque composition may explain this discrepancy. We aimed in the present study to assess the effect of statin therapy on coronary plaque composition and plaque volume using serial multimodality imaging. From an open-label, single-blinded study, patients with angiographically mild-to-moderate lesion were randomized to receive atorvastatin 60 (AT 60) mg or atorvastatin 20 (AT 20) mg for 12 months. Optical coherence tomography was used to assess fibrous cap thickness (FCT) and intravascular ultrasound to assess atheroma burden at 3 time points: baseline, at 6 months, and at 12 months. Thirty-six lipid-rich plaques in 27 patients with AT 60 mg and 30 lipid-rich plaques in 19 patients with AT 20 mg were enrolled in this study. Low-density lipoprotein cholesterol level was significantly decreased at 6 months without further reduction at 12 months. AT 60 mg induced greater reduction in low-density lipoprotein cholesterol compared with AT 20 mg. Optical coherence tomography revealed continuous increase in FCT from baseline to 6 months and to 12 months in both groups. AT 60 mg induced greater increase in FCT compared with AT 20 mg at both follow-up points. The prevalence of thin-cap fibroatheroma and the presence of macrophage at 6 months were significantly lower in AT 60 mg compared with AT 20 mg. Plaque burden did not change significantly in both groups. In conclusion, both intensive and moderate statin therapy stabilizes coronary plaques, with a greater benefit in the intensive statin group. However, no significant changes in plaque volume were observed over time regardless of the intensity of statin therapy.